JavaScript Engineer, Inventory Quality

The Inventory Quality team at Quantcast is responsible for ensuring that we only run our customers’ ads on brand-safe, fraud-free sites and to real humans.  We are looking for experienced JavaScript engineers to help with this mission.
As a JavaScript Engineer, you write client-side JavaScript to capture and process anonymous ad and Internet usage data on millions of pageviews per day. This data informs advertising purchasing strategy and our anti-fraud and brand safety systems. You care about clean and performant code, how to test code effectively across browsers and how to A/B test new features online.


  • Design and improve JavaScript that renders ads intelligently on websites
  • Write JavaScript that collects contextual browser information and behavioural data across millions of websites and users
  • Build browser extensions and crawlers that track advertising trends across the web
  • Work with data scientists to invent novel approaches to fighting fraudulent ad traffic 


  • BS in Computer Science, related field or equivalent experience
  • Expert knowledge of JavaScript and object-oriented programming with JS
  • Deep understanding of cross-browser differences
  • Knowledgeable in JS programming best practices and design patterns
  • Ability to write modular, testable, and readable JS code
  • Understanding of JS performance tradeoffs, and profiling and debugging tools
  • Working knowledge of test frameworks
  • Resourceful, experimentation-driven approach to solving unstructured, data-oriented JS challenges

Quantcast is a fast-growing, late-stage, pre-IPO startup headquartered in San Francisco with offices around the world. We are committed to creating an inclusive and diverse environment where everyone can confidently be their authentic self.

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